Generally speaking, texting in the dark will do some harm to your eyes. As we all know that while texting the dark, we have to strain our eyes to focus on something, like the screen of the computer. If you text in the dark for a long time, the nerve around your eyes will keep strained, and then your eyes are easily to get infected and then I think the victim will be you and your eyes. As a matter of the fact, there are more possibilities for your eyes to get infection and bloodshot and irritated. However, if you have already been wearing glasses for some time, you can text in the dark, but pls keep in mind that you cannot do it for long time. Because the prescription glasses can adjust the distance between you and your computer so that you do not need to make your nerves strained for long time, you can solve some emergency when you have to text in the bark. No matter whether you text in the dark or not, you should make your eyes have a rest after working. Hope this help you.